Automatic choke release



I Sept. 1, 1936 BQURN 2,052,601

AUTOMATIC CHOKE RELEASE Filed Aug. 28, 1935 2 Sheets-Sheet 1 Irma/frSept. 1, 1936.

I H.- H. BOURN AUTOMATIC CHOKE RELEASE Filed Au 28, 1935' 2 Sheets-Sheet2 m H x m mud 7n 2 Patented Sept. 1, 1936 UNITED STAS 2,052,601AUTOMATIC CHOKE RELEASE Harry H. Bourn, Waukesha, Wis.

Application August 28, 1935, Serial No. 38,188

4 Claims.

7 choking the engine and is customarily carried out by a butterfly valvein the air intake controlled from the dash (in the automobile) by achoke rod. However, it is injurious to carry this action too far in thatthe cylinders will become flooded with gasoline and the engine will bewell Another object is to provide an automatic choke release which willnot interfere in any way with the normal manual choking of the enginebut which as soon as the engine starts and sets -up 'a pressure in theexhaust will automatically open the choke valve.

Another object is to provide a device of this kind comprising a chokevalve in the air intake of the engine, a choke valve operatingdevicecomprising a lever connected to the choke, slide rods connectedto' the usual manual choke control wire and resiliently connected to thelever whereby the normal movement of the choke control wire will swingsaid lever and close the choke valve to choke the engine, and an exhaustpressure controlled valve connected to the said lever whereby the samewill be swung to position opening the choke valve as soon as an exhaustpressure is set up in the exhaust pipe by the engine starting. 1

With these and other objects in view the invention resides in the novelconstruction and arrangementof parts as hereinafter fully .set forth andclaimed, reference being had to the accompany drawings wherein:

Figure 1 is a side elevation of my' invention as in position for useupon the intake and exhaust elements of an engine and showing theconnection of the usual manual choke control wire.

' Figure 2 is an enlarged perspective view of the choke valve operatingmechanism alone.

Figure 3 is an enlarged side elevation of the control valve housing andassociated parts.

Figure 4 is a cross section along the line 4-4 5 in .Figure 3. 1

Figure 5 is a cross section along the line 5-5 in Figure 3.

Referring now with more particularity to the drawings the referencecharacter A designatesthe intake manifold, B the exhaust manifold, C thecarburetor, D the choke valve in the air intake pipe E, and F theexhaust pipe, all being the conventional parts of an internal combustionengine not shown. The choke valve D is provided with a, crank G and thiscrank is normally 1 attached to a manual choke wire H which leads backthrough tubing I to the instrument board J where a button K is afiixedso that by pulling out on this button the valve D is closed (theposition shown). holds the choke D in open position.

My invention comprises a choke valve operating mechanism or assemblydesignated generally at G and made up of a frame 7 formed from heavysheet metal to provide an elongated base 8 and upturned ends 9terminating at their upper ends in out-thrust lips it). Bearing ears Hare turned up from the lateral margins of the base 8 near the centerthereof and have apertures l2 through which a shaft I3 is journaled andextended across and above the upper face of said base. A lever I4 isapertured at one end at [5 to receive the shaft and is split andprovided with a clamping screw 16 by which the lever is rigidly anchoredto the shaft l3 at a medial point between the ears ll ext/endingupwardly at its free end H from the base 8.

The ends 9 each have a pair of spaced slide rod apertures i8 near theirupper extremities and spaced parallel slide rods [9 and 2B are slidablymounted and project at each end through these apertures. Bearing blocks2| of wood or other suitable material are secured by screws 22 beneaththe aforesaid lips l0 and have apertures 23 passing and supporting theends of the slide rods l9 and 2!). Intermediate their ends the sliderods l9 and 2B are joined by spaced cross bars 26 and 25 apertured at 26near their ends to take the rods and split and provided with clampscrews 2? to secure them solidly to the rods. The cross bars are set farenough apart to clear both the ends 9 a substantial distance and toallow plenty of play for the lever H3. One, cross bar, as 24, (the oneremote from the choke valve D when in use) has a central aperture 28 inwhich the end of the choke control wire H is mounted and secured by aset screw 29 and the adjacent end and bearing block 2| are centrallyapertured at 39 to pass this wire H and its surrounding guide tubing I.The said block 2| Normally a spring as shown at L is slotted at 3!adjacent the aperture 39 and the screws 22 compress the block on thetubing I to anchor it in place.

The other cross bar 25 also'has a central aperture 32 through which aconnecting rod 33 is slidably mounted, the said rod having. a head 34 atone end which is placed in a slot or fork 35 in the aforesaid free endll of the lever I4 where it is pivoted by a pin 36. An expansion coilspring 3? is coiled. around the connecting rod 33 and braced between thehead 34 and the cross bar 24 and normally urges the said cross barforwardly away from the lever l4. A stop collar 38 secured by a setscrew 39 to the extended end of the connnecting rod limits this movementas it strikes the said cross bar 25. An operating rod id is pivoted at41 in the fork 35 in the lever i4 above the said connecting rod head 34and extends to the operating crank G of the choke valve D where it ispivotally attached as shown.

The operating mechanism as thus far described is mounted in any suitablemanner on the en-' gine preferably at the rear of the carburetor C butin any position so that with the operating rod. connected as describedthe normal position of the parts will hold the choke valve D in open orrunning position. Then a pull on the choke control wire H will pull theslide rods i9 and 29 sliding them through their mounting blocks andapertures and compressing spring 3? until the pressure on the lever i4swings it to the rear. and closes the choke valve D to choke the enginein usual manner. It will thus be evident that this device interferes inno way with the normal manual manipulation of the choke by its controlwire.

An exhaust control valve assembly is provided comprising a housing 42 ofelongated form of inverted box-shaped form at its center section 43 andwith reduced ends 44 and 45 arcuate or semicircular in cross section asshown. haust pipe F has an upper half portion sawed or cut out as shownat F in Figures 3 and 4 and the housing 42 is set over the pipe with thecenter section 43 resting over this cut out and the ends 44 and 45fitting closely around the pipe at each end of the out out. Annularparted clamp bands '46 are then placed over the ends 44 and 45 and thepipe F and the clamp screws 41 drawn tight rigidly mounting the housing42 on the pipe. It will be noted that the lower side margins 48 of thehousing depend down past the lower edges of the cut out or opening F andlong strip gaskets 49 are placed between these margins and the pipe toprevent the escape of gases from the pipe. The

extremities of the said lower margins 48 of the extended out a shortdistance around these apertures. A shaft 56 is journaled through theseapertures 53 and a valve blade 5'! is riveted or otherwise secured at 58to the shaft within the housing. This blade 51 is flat and of such shapeand'size that it may swing downward into the pipeF or. upward clear ofthe pipe into the housing 42' and .in the former position willsubstantially close all passage through the pipe as shown.

2,052,601 7 7. One end of the shaft 56 is extended as at 59 and The exalever 60 is secured by its aperture Bland split clamping arrangement 62thereon. The face of the lever 60 adjacent the extension sleeve 55 onthat side hasa recess 63 receiving an asbestos packing gasket to preventthe escape of gas around the shaft at that point. A' packing cap' orgland 65 is threaded over the sleeve 55 on the this opening. A centerclamp band'H is placed over the pipe F, housing 42 and this cap 69 andthe screws 12 drawn tight to press the cap to its seat. An asbestosgasket 73 may be placed within the cap to seal the joint and the cap mayhave a boss 73 engaging a socket i4 in -the band H to locate the cap andband In use the housing 42 is mounted as described on the exhaust pipe Fbelow and to the rear of the choke operating unit previously describedand with the side ofthe housing at which the shaft 56;; V is mountedturned to the front or towardthe:

engine. parted clamping end '15 to the extended end'rof the aforesaidshaft 13 and the forked ends ll of;

this lever and the lever 60 are pivotally connected by a control rod-13pivotally mounted at its ends at l9 to the said lever as shown. Axialdisplacement of the shaft I3 may be prevented by: a bearing collar 88secured by a set screw 8 I to the shaft within the adjacent bearing earU A lever i5 is secured by its apertured' With the parts arranged asshown andf dea scribed the aforesaid swinging of the lever I4,

back to close the choke valve D will swing the valve blade 51 down intothe exhaust pipe F as shown in Now as soon as the engine starts'the.

Figure 1.

pressure of the exhaust gas in .theipipe will swing; the valve blade 57back up into-the housing clear;

of the pipe and the resulting movement ,of the.

connected levers BOand 15 will swinggthe operating lever 1 backforwardly; and will open the choke valve D holding the same in thisposition and returning the parts to their initial positions;

as will be understood. Since this action is auto-g matic and undercontrollof the starting of the engine excess chokingwill be entirelyprevented.

While I have herein set forth. acertain pre- V ferred embodiment of myinvention, it is understood that I may vary fromthe; same in minor;

structural details, so as best 'to'construct; a practicaldevicefor thepurpose intended; not depart ing from the spirit of the invention andwithinthe scope of the appended claims. j-

Iclaimz; I 1. In'combination with the chokevalve, man;

ual choke control wireand exhaust pipe .of an automobile, a chokevalveoperating mechanism comprising a frame, an operating lever pivotedin V the frame and connected'to the-choke valve, a, slide rod assemblyslidablymounted; in theframe and resiliently connected to-the lever, the:said

slide rod assembly being'also connected to the;

manual choke control wire whereby manipulation of this wire will operate:the lever. to close. the said choke valve, and a'control valve'mechanism will open the choke valve. 5

attached to the exhaust pipe and to the 'said'opf erating lever wherebypressure in the exhaust pipe 2. 'In combination with the chokevalve'pchbke valve control wire and exhaust pipe of" an automobileengine, a choke valve operating mechanism comprising a frame, anoperating lever pivotally mounted in the frame and connected to thechoke valve, slide rods slidably mounted in the frame at each side ofthe lever, cross bars secured to the slide rods, the said choke valvecontrol wire being secured to one cross bar, the other cross bar havingan aperture, a connecting rod pivotally connected to the lever andslidably mounted through the said aperture, an expansion coil springcoiled over the connecting rod and braced between the lever and thecross bar, a stop collar at the end of the connecting rod on the side ofthe cross bar remote from the spring, and a control assembly mounted onthe exhaust pipe and controlled by the pressure therein to actuate thesaid operating lever and open the choke valve.

7 3. In combination with the choke valve, choke valve control wire andexhaust pipe of an automobile engine, a choke valve operating mechanismcomprising a frame, an operating lever pivotally mounted in the frameand connected to the choke valve, slide rods slidably mounted in theframe at each side of the lever, cross bars secured to the slide rods,the said choke valve control wire being secured to one cross bar, theother cross bar having an aperture, a connecting rod pivotally connectedto the lever and slidably mounfted through the said aperture, anexpansion coil spring coiled over the connecting rod and braced betweenthe lever and the cross bar, a stop collar at the end of the connectingrod on the side of the cross bar remote from the spring, a housingmounted on the exhaust pipe, the said pipe having an opening into thesaid housing, a valve blade pivotally mounted in the housing and adaptedto swing into the exhaust pipe through the said opening therein, andmeans connecting the said valve blade and operating lever whereby thechoke valve will be opened by exhaust pressure in the exhaust pipe.

4. In combination with the choke valve, choke valve control wire andexhaust pipe of an automobile engine, a choke valve operating mechanismcomprising a frame, an operating lever pivotally mounted in the frameand connected to the choke valve, slide rods slidably mounted in theframe at each side of the lever, cross bars secured to the slide rods,the said choke valve control wire being secured to one cross bar, theother cross bar having an aperture, a connecting rod pivotally connectedto the lever and slidably mounted through the said aperture, anexpansion coil spring coiled over the connecting rod and braced betweenthe lever and the cross bar, a stop collar at the end of the connectingrod on the side of the cross bar remote from the spring, a housingcomprising a square inverted boxshaped central section and arcuate endsseated over the exhaust pipe, clamps around the said ends and the pipe,the said pipe having an opening communicating with the said centralsection of the housing, a shaft journaled through the center sectionofthe housing adjacent the frontal end thereof, a valve blade secured tothe shaft within the housing, a lever secured to the shaft outside thehousing, a lever attached to the said operating lever of the valveoperating mechanism, and a link connecting the said levers.

HARRY H. BOURN.

